Synthesis of fatty ester derived novel multifunctional additive and its performance evaluation in polyol base oil

Abstract

The organometallics like ZDDPs are widely used as multifunctional additives in lubricants for imparting antiwear, antioxidant, and corrosion inhibitor activity. Since it has toxic elements like P, Zn, and S so it is an environmentally toxic, non-biodegradable, and ash-forming additive. In automotive emissions, it also causes poisoning in catalytic converters. Due to environmental concerns, it is an issue of awareness to discover less toxic alternatives for these multifunctional additives despite their potent and economical properties. In this work, MO was reacted in a stoichiometric ratio with Tga, giving the intermediate compound MO-Tga through thiol-ene coupling. Subsequently, the reaction of MO-Tga with PPA gave a novel multifunctional additive MO-Tga-PPA. The molecular characteristics and thermal stability of MO-Tga-PPA were studied using techniques like NMR, FTIR, and TGA. The additive was doped at various concentrations such as 1000, 2000, 3000, 4000, and 5000 ppm in polyol to examine their antiwear, antifriction, antioxidant, and anticorrosion performance. It reveals the maximum reduction of 53.85% in the average COF and 25.51% in AWSD at 5000 ppm. The antioxidant activity shows a maximum free radicals inhibition of 97.9% at 3000 ppm using the DPPH. As far as the anticorrosion activity is concerned, the values for the penetration rate, corrosion rate, and weight loss were reduced to 0.015 mpy, 0.082 mdd, and 0.08 mg from the observed values of 0.114 mpy, 0.62 mdd, and 0.60 mg in polyol base oil was observed at 4000 ppm.

Graphical Abstract

COF vs. time graphs for developed additive when blended in different concentrations in base oil.